Romidepsin, also known as FK228 and FR901228, is a potent histone deacetylase inhibitor. The chemical structure of romidepsin is depicted below as Formula I.

U.S. Pat. No. 4,977,138 describes preparation of romidepsin by culturing microorganism Chromobacterium violaceum WB968. Romidepsin is isolated from fermentation broth by extraction and column chromatography.
U.S. Pat. No. 7,396,665 provides an alternative process for the preparation of romidepsin which requires carrying out four column chromatographic purifications steps.
US2009/0186382 states that above published processes for the isolation of romidepsin does not produce pure romidepsin consistently. US'382 application then goes on to describe an alternative process for the preparation of pure romidepsin to avoid drawbacks of above published processes. US'382 process is carried out at specific pH range and involves use of four chromatographic purifications and two crystallization steps.
A process disclosed in U.S. Pat. No. 4,977,138 for the preparation of romidepsin crystal requires use of three solvents and provides crystals having higher residual solvent content. An improved process described in U.S. Pat. No. 7,611,724 involves use of two solvents which must be used in the specific concentration. Hence, there is a need to provide a simpler process which has a small number of purification steps and requires less time for the isolation of pure romidepsin.